1. Field of the Invention
The present invention relates to a conductor strip used for making an electrical connection between a printed circuit and a battery. It also relates to a connecting arrangement of such a conductor strip and a circuit board.
2. Description of the Related Art
Recently portable electronic devices including notebook computers, cell phones, etc., have been widely used because of their handiness. For enabling outside use, the cell phone for example operates on a rechargeable battery housed in a battery pack together with other necessary components. The battery pack, readily detachable for exchange of the battery, includes a battery cell and a protection unit connected to the cell for preventing the cell from over-discharging or being overcharged.
FIG. 16 shows some aspects of a conventional protection unit U0 of the above type. As illustrated, the conventional unit U0, used for a rechargeable battery cell 100, includes a printed circuit board 200, electronic components 300 mounted on the board 200, and two conductor strips 400 connected to the battery cell 100. Each of the conductor strips 400 includes a rectangular connecting portion 400a and another rectangular connecting portion 400b. The first connecting portion 400a is soldered to a pad (not shown) provided on the board 200, while the second connecting portion 400b is welded to the cathode or anode (not shown) of the cell 100. The conductor strip 400 is bent so that the second connecting portion 400b is perpendicular to the first connecting portion 400a. 
While the conventional conductor strip 400 has a simple configuration and thus can be made easily, it entails the following drawbacks.
As seen from FIG. 16, the first connecting portion 400a of the conventional strip 400 does not have any holes or gaps in it. Thus, it is impossible to observe the bonding condition of the solder after the applied solder hardens between the connecting portion 400a and the board 200. Another problem is that the conductor strip 400 is detached from the board 200 rather easily, due to its simple structure, upon exertion of an upward force on the second portion 400b. 
The present invention has been proposed under the circumstances described above. It is, therefore, an object of the present invention to provide a conductor strip that can be firmly attached to a printed circuit board and also permits easy inspection of the solder-bonding condition.
According to a first aspect of the present invention, there is provided a conductor strip comprising: a first end portion fixed to a first member; a second end portion fixed to a second member; and a connector arranged between the first end portion and the second end portion. The connector is smaller in size than the first end portion in a width direction perpendicular to another direction connecting the first end portion and the second end portion.
Preferably, the connector may extend from a central part of the first end portion.
Preferably, the conductor strip may further comprise a projection disposed adjacent to the connector, wherein the projection extends from the first end portion toward the second end portion.
Preferably, the connector may comprise two connecting portions spaced from each other in the width direction.
Preferably, a U-shaped slit may be formed in the conductor strip.
Preferably, the first end portion may be soldered to the first member. The second end portion may be welded to the second member.
According to a second aspect of the present invention, there is provided a conductor strip that comprises: a first end portion fixed to a first member; and a second end portion fixed to a second member. The first end portion is formed with a plurality of grooves for improving the bonding strength of solder material applied between the first end portion and the first member.
Preferably, each of the grooves may have a triangular cross section.
Preferably, the plurality of grooves may comprise grooves that perpendicularly intersect each other.
According to a third aspect of the present invention, there is provided an assembly that comprises: a conductor strip that includes a first end portion, a second end portion, and a connector disposed between the first and the second end portions; and a substrate that supports the conductor strip. The connector is smaller in width than the first end portion.
Preferably, the connector may at least partially project from the substrate.
According to a fourth aspect of the present invention, there is provided a method of soldering a conductor strip to a supporting member, wherein the conductor strip is formed with a U-shaped slit. The method comprises the steps of: applying solder paste to the supporting member in a manner such that a solder-void region is formed on the supporting member; positioning the conductor strip on the supporting member; and melting the applied solder paste. The conductor strip is positioned on the supporting member so that the U-shaped slit exposes the solder-void region.
Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings.